Remove the suser(9) interface from the kernel. It has been replaced from

years by the priv_check(9) interface and just very few places are left.
Note that compatibility stub with older FreeBSD version
(all above the 8 limit though) are left in order to reduce diffs against
old versions. It is responsibility of the maintainers for any module, if
they think it is the case, to axe out such cases.

This patch breaks KPI so __FreeBSD_version will be bumped into a later
commit.

This patch needs to be credited 50-50 with rwatson@ as he found time to
explain me how the priv_check() works in detail and to review patches.

Tested by:      Giovanni Trematerra <giovanni dot trematerra at gmail dot com>
Reviewed by:    rwatson

12 files changed, 46 insertions, 171 deletions

diff --git a/ObsoleteFiles.inc b/ObsoleteFiles.inc
index 85e10be..445e6c1 100644
--- a/ObsoleteFiles.inc
+++ b/ObsoleteFiles.inc
@@ -14,6 +14,8 @@
 # The file is partitioned: OLD_FILES first, then OLD_LIBS and OLD_DIRS last.
 #
 
+# 20080917: removal of manpage for axed kernel primitive suser(9)
+OLD_FILES+=usr/share/man/man9/suser.9
 # 20080913: pax removed from rescue
 OLD_FILES+=rescue/pax
 # 20080823: removal of unneeded pt_chown, to implement grantpt(3)
diff --git a/share/man/man9/Makefile b/share/man/man9/Makefile
index 54108ab..cc600ee 100644
--- a/share/man/man9/Makefile
+++ b/share/man/man9/Makefile
@@ -225,7 +225,6 @@ MAN=	accept_filter.9 \
 	stack.9 \
 	store.9 \
 	style.9 \
-	suser.9 \
 	swi.9 \
 	sx.9 \
 	SYSCALL_MODULE.9 \
@@ -1108,7 +1107,6 @@ MLINKS+=store.9 subyte.9 \
 	store.9 suswintr.9 \
 	store.9 susword.9 \
 	store.9 suword.9
-MLINKS+=suser.9 suser_cred.9
 MLINKS+=swi.9 swi_add.9 \
 	swi.9 swi_sched.9
 MLINKS+=sx.9 sx_assert.9 \
diff --git a/share/man/man9/priv.9 b/share/man/man9/priv.9
index 2756da9..def1ca3 100644
--- a/share/man/man9/priv.9
+++ b/share/man/man9/priv.9
@@ -48,7 +48,7 @@ passed thread,
 .Fa td ,
 or credential,
 .Fa cred .
-This interface replaces the
+This interface replaces the now removed
 .Xr suser 9
 privilege checking interface.
 Privileges typically represent rights in one of two categories: the right to
@@ -112,7 +112,6 @@ failure occurred.
 .Sh SEE ALSO
 .Xr jail 2 ,
 .Xr mac 9 ,
-.Xr suser 9 ,
 .Xr ucred 9
 .Sh AUTHORS
 The
diff --git a/share/man/man9/suser.9 b/share/man/man9/suser.9
deleted file mode 100644
index 5411955..0000000
--- a/share/man/man9/suser.9
+++ /dev/null
@@ -1,115 +0,0 @@
-.\"
-.\" Copyright (c) 1996 Julian R Elischer
-.\" All rights reserved.
-.\"
-.\" This code is derived from software contributed by Kenneth Stailey.
-.\"
-.\" Redistribution and use in source and binary forms, with or without
-.\" modification, are permitted provided that the following conditions
-.\" are met:
-.\" 1. Redistributions of source code must retain the above copyright
-.\"    notice, this list of conditions and the following disclaimer.
-.\" 2. Redistributions in binary form must reproduce the above copyright
-.\"    notice, this list of conditions and the following disclaimer in the
-.\"    documentation and/or other materials provided with the distribution.
-.\" 3. The name of the author may not be used to endorse or promote products
-.\"    derived from this software without specific prior written permission.
-.\"
-.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
-.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
-.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
-.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
-.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
-.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
-.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
-.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-.\" SUCH DAMAGE.
-.\"
-.\" $FreeBSD$
-.\"
-.Dd August 30, 2007
-.Dt SUSER 9
-.Os
-.Sh NAME
-.Nm suser ,
-.Nm suser_cred
-.Nd check if credentials have superuser privileges
-.Sh SYNOPSIS
-.In sys/priv.h
-.Ft int
-.Fn suser "struct thread *td"
-.Ft int
-.Fn suser_cred "struct ucred *cred" "int flag"
-.Sh DESCRIPTION
-The
-.Fn suser
-and
-.Fn suser_cred
-functions check if the credentials given include superuser powers.
-.Pp
-These interfaces have now been obsoleted by
-.Xr priv 9 ,
-and are provided only for compatibility with third party kernel modules that
-have not yet been updated to the new interface.
-They should not be used in any new kernel code.
-.Pp
-The
-.Fn suser
-function is the most common, and should be used unless special
-circumstances dictate otherwise.
-.Pp
-The
-.Fn suser_cred
-function should be used when the credentials to be checked are
-not the thread's own, when there is no thread, when superuser
-powers should be extended to imprisoned roots, or when the credential
-to be checked is the real user rather than the effective user.
-.Pp
-Whether or not a privilege is permitted in a
-.Xr jail 8
-depends on logic in
-.Fn prison_priv_check .
-.Pp
-In general, privileges are assigned based on the effective user ID; in some
-cases, the real user ID may be used.
-.Pp
-The
-.Fa flags
-field is currently unused.
-.Pp
-The
-.Fn suser
-and
-.Fn suser_cred
-functions note the fact that superuser powers have been used in the
-process structure of the process specified.
-Because part of their function is to notice
-whether superuser powers have been used,
-the functions should only be called after other permission
-possibilities have been exhausted.
-.Sh RETURN VALUES
-The
-.Fn suser
-and
-.Fn suser_cred
-functions return 0 if the user has superuser powers and
-.Er EPERM
-otherwise.
-This is the
-.Em reverse logic
-of some other implementations of
-.Fn suser
-in which a TRUE response indicates superuser powers.
-.Sh SEE ALSO
-.Xr chroot 2 ,
-.Xr jail 2 ,
-.Xr priv 9
-.Sh BUGS
-The
-.Fn suser
-and
-.Fn suser_cred
-functions do not, in fact, record that superuser privileges have been
-used, and have not done so since August 2000.
diff --git a/share/man/man9/ucred.9 b/share/man/man9/ucred.9
index bd16fe3..40933a2 100644
--- a/share/man/man9/ucred.9
+++ b/share/man/man9/ucred.9
@@ -163,12 +163,6 @@ In these circumstances, the thread credential
 should be used, as it requires no locking to access safely, and remains stable
 for the duration of the call even in the face of a multi-threaded
 application changing the process credentials from another thread.
-Primitives such as
-.Xr suser 9
-will assume the use of
-.Va td_ucred
-unless explicitly specified using
-.Xr suser_cred 9 .
 .Pp
 During a process credential update, the process lock must be held across
 check and update, to prevent race conditions.
diff --git a/share/man/man9/vfs_suser.9 b/share/man/man9/vfs_suser.9
index 749557a..df68bc2 100644
--- a/share/man/man9/vfs_suser.9
+++ b/share/man/man9/vfs_suser.9
@@ -46,7 +46,7 @@ It will check to see if the thread
 passed in has the same credentials as the user that mounted the
 file system.
 If so, it returns 0, otherwise it returns what
-.Xr suser 9
+.Xr priv_check 9
 would have returned.
 .Sh RETURN VALUES
 The
@@ -61,8 +61,7 @@ of some other implementations of
 in which a TRUE response indicates superuser powers.
 .Sh SEE ALSO
 .Xr chroot 2 ,
-.Xr jail 2 ,
-.Xr suser 9
+.Xr jail 2
 .Sh HISTORY
 The
 .Fn vfs_suser
diff --git a/sys/dev/cxgb/ulp/tom/cxgb_cpl_io.c b/sys/dev/cxgb/ulp/tom/cxgb_cpl_io.c
index 952a05b..b12c367 100644
--- a/sys/dev/cxgb/ulp/tom/cxgb_cpl_io.c
+++ b/sys/dev/cxgb/ulp/tom/cxgb_cpl_io.c
@@ -1663,8 +1663,8 @@ t3_ip_ctloutput(struct socket *so, struct sockopt *sopt)
 	if (error)
 		return (error);
 
-	if (optval > IPTOS_PREC_CRITIC_ECP && !suser(curthread))
-		return (EPERM);
+	if (optval > IPTOS_PREC_CRITIC_ECP)
+		return (EINVAL);
 
 	inp = so_sotoinpcb(so);
 	inp_wlock(inp);
diff --git a/sys/kern/kern_priv.c b/sys/kern/kern_priv.c
index 87cce77..100f6d4 100644
--- a/sys/kern/kern_priv.c
+++ b/sys/kern/kern_priv.c
@@ -133,24 +133,3 @@ priv_check(struct thread *td, int priv)
 
 	return (priv_check_cred(td->td_ucred, priv, 0));
 }
-
-/*
- * Historical suser() wrapper functions, which now simply request PRIV_ROOT.
- * These will be removed in the near future, and exist solely because
- * the kernel and modules are not yet fully adapted to the new model.
- */
-int
-suser_cred(struct ucred *cred, int flags)
-{
-
-	return (priv_check_cred(cred, PRIV_ROOT, flags));
-}
-
-int
-suser(struct thread *td)
-{
-
-	KASSERT(td == curthread, ("suser: td != curthread"));
-
-	return (suser_cred(td->td_ucred, 0));
-}
diff --git a/sys/netipx/ipx.c b/sys/netipx/ipx.c
index 5ae0d4b..5761636 100644
--- a/sys/netipx/ipx.c
+++ b/sys/netipx/ipx.c
@@ -99,7 +99,7 @@ ipx_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
 	struct ifaddr *ifa;
 	struct ipx_ifaddr *oia;
 	int dstIsNew, hostIsNew;
-	int error = 0;
+	int error = 0, priv;
 
 	/*
 	 * Find address for this interface, if it exists.
@@ -135,12 +135,13 @@ ipx_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
 		return (0);
 	}
 
-	if (td && (error = suser(td)) != 0)
-		return (error);
-
 	switch (cmd) {
 	case SIOCAIFADDR:
 	case SIOCDIFADDR:
+		priv = (cmd == SIOCAIFADDR) ? PRIV_NET_ADDIFADDR :
+		    PRIV_NET_DELIFADDR;
+		if (td && (error = priv_check(td, priv)) != 0)
+			return (error);
 		if (ifra->ifra_addr.sipx_family == AF_IPX)
 		    for (oia = ia; ia != NULL; ia = ia->ia_next) {
 			if (ia->ia_ifp == ifp  &&
@@ -154,6 +155,8 @@ ipx_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
 
 	case SIOCSIFADDR:
 	case SIOCSIFDSTADDR:
+		if (td && (error = priv_check(td, PRIV_NET_SETLLADDR)) != 0)
+			return (error);
 		if (ia == NULL) {
 			oia = (struct ipx_ifaddr *)
 				malloc(sizeof(*ia), M_IFADDR,
@@ -183,6 +186,10 @@ ipx_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
 				ia->ia_broadaddr.sipx_addr.x_host = ipx_broadhost;
 			}
 		}
+		break;
+	default:
+		if (td && (error = priv_check(td, PRIV_NET_HWIOCTL)) != 0)
+			return (error);
 	}
 
 	switch (cmd) {
diff --git a/sys/nfsserver/nfs_serv.c b/sys/nfsserver/nfs_serv.c
index 15c6624..901a4bd 100644
--- a/sys/nfsserver/nfs_serv.c
+++ b/sys/nfsserver/nfs_serv.c
@@ -1802,7 +1802,8 @@ nfsrv_create(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
 			if (vap->va_type == VCHR && rdev == 0xffffffff)
 				vap->va_type = VFIFO;
                         if (vap->va_type != VFIFO &&
-                            (error = suser_cred(cred, 0))) {
+			    (error = priv_check_cred(cred, PRIV_VFS_MKNOD_DEV,
+			    0))) {
 				goto ereply;
                         }
 			vap->va_rdev = rdev;
@@ -2024,7 +2025,8 @@ nfsrv_mknod(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
 		if (error)
 			NDFREE(&nd, NDF_ONLY_PNBUF);
 	} else {
-		if (vtyp != VFIFO && (error = suser_cred(cred, 0)))
+		if (vtyp != VFIFO && (error = priv_check_cred(cred,
+		    PRIV_VFS_MKNOD_DEV, 0)))
 			goto out;
 		error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, vap);
 		if (error) {
diff --git a/sys/security/mac_bsdextended/mac_bsdextended.c b/sys/security/mac_bsdextended/mac_bsdextended.c
index cb993db..93befae 100644
--- a/sys/security/mac_bsdextended/mac_bsdextended.c
+++ b/sys/security/mac_bsdextended/mac_bsdextended.c
@@ -221,7 +221,7 @@ static int
 ugidfw_rulecheck(struct mac_bsdextended_rule *rule,
     struct ucred *cred, struct vnode *vp, struct vattr *vap, int acc_mode)
 {
-	int match;
+	int mac_granted, match, priv_granted;
 	int i;
 
 	/*
@@ -372,9 +372,31 @@ ugidfw_rulecheck(struct mac_bsdextended_rule *rule,
 	}
 
 	/*
+	 * MBI_APPEND should not be here as it should get converted to
+	 * MBI_WRITE.
+	 */
+	priv_granted = 0;
+	mac_granted = rule->mbr_mode;
+	if ((acc_mode & MBI_ADMIN) && (mac_granted & MBI_ADMIN) == 0 &&
+	    priv_check_cred(cred, PRIV_VFS_ADMIN, 0) == 0)
+		priv_granted |= MBI_ADMIN;
+	if ((acc_mode & MBI_EXEC) && (mac_granted & MBI_EXEC) == 0 &&
+	    priv_check_cred(cred, (vap->va_type == VDIR) ? PRIV_VFS_LOOKUP :
+	    PRIV_VFS_EXEC, 0) == 0)
+		priv_granted |= MBI_EXEC;
+	if ((acc_mode & MBI_READ) && (mac_granted & MBI_READ) == 0 &&
+	    priv_check_cred(cred, PRIV_VFS_READ, 0) == 0)
+		priv_granted |= MBI_READ;
+	if ((acc_mode & MBI_STAT) && (mac_granted & MBI_STAT) == 0 &&
+	    priv_check_cred(cred, PRIV_VFS_STAT, 0) == 0)
+		priv_granted |= MBI_STAT;
+	if ((acc_mode & MBI_WRITE) && (mac_granted & MBI_WRITE) == 0 &&
+	    priv_check_cred(cred, PRIV_VFS_WRITE, 0) == 0)
+		priv_granted |= MBI_WRITE;
+	/*
 	 * Is the access permitted?
 	 */
-	if ((rule->mbr_mode & acc_mode) != acc_mode) {
+	if (((mac_granted | priv_granted) & acc_mode) != acc_mode) {
 		if (ugidfw_logging)
 			log(LOG_AUTHPRIV, "mac_bsdextended: %d:%d request %d"
 			    " on %d:%d failed. \n", cred->cr_ruid,
@@ -400,12 +422,6 @@ ugidfw_check(struct ucred *cred, struct vnode *vp, struct vattr *vap,
 	int error, i;
 
 	/*
-	 * XXXRW: More specific privilege selection needed.
-	 */
-	if (suser_cred(cred, 0) == 0)
-		return (0);
-
-	/*
 	 * Since we do not separately handle append, map append to write.
 	 */
 	if (acc_mode & MBI_APPEND) {
diff --git a/sys/sys/priv.h b/sys/sys/priv.h
index 4c0fdca..c56c99d 100644
--- a/sys/sys/priv.h
+++ b/sys/sys/priv.h
@@ -485,12 +485,6 @@ struct thread;
 struct ucred;
 int	priv_check(struct thread *td, int priv);
 int	priv_check_cred(struct ucred *cred, int priv, int flags);
-
-/*
- * Continue to support external modules that rely on suser(9) -- for now.
- */
-int	suser(struct thread *td);
-int	suser_cred(struct ucred *cred, int flags);
 #endif
 
 #endif /* !_SYS_PRIV_H_ */